Installation
1
18
Installation and servicing instructions condensing gas boiler 800 - 24/29/43/60 and 800 - 24T25/29T25 H/V • edition 02/2006
Subject to modifications resulting from technical improvements !
Buderus • http://buderus-domestic.co.uk
1.9.2
Wiring Diagram
fig. 20 Wiring diagram
24 VA
C
0 VA
C
0
max 6 V
A
12
RC
1)
12
Incandescent
fir
ing electrode
Remo
v
e
br
idge when
carr
ying out connection
12
12
34
M
N
L
12
M
23
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
20 pin connection str
ip
18 pin connection str
ip
12
34
56
78
9
1
1
10
24V output (A
C)
Exter
nal sensor
Fuse
, main s
witch, emergency OFF s
witches and saf
ety
measures to comply with local regulations and standards
STB
MV2
MV1
HT1
HT2
24Vdc
AT
B
PA
FR
FS
FB
FK
Flame-monitoring electrode
Note:
Circulation pump (PH)
(max.
2A)
KIM
V
entilator
230V 50Hz
Mains po
w
er source
~
1)
Only one room-temper
ature regulating
de
vice ma
y be connected.
A
T
B
Flue-gas temper
ature-limiting de
vice
FB
Mains-w
ater temper
ature sensor
FK
Boiler w
ater-temper
ature sensor (supply)
FR
Retur
n-temper
ature sensor (retur
n)
FS
Saf
ety-temper
ature sensor (saf
ety)
HT
Hand-held ter
minal
KIM
Boiler identification module
MV1
1.
Solenoid v
alv
e
MV2
2.
Solenoid v
alv
e
P
A
P
otential-free connection (br
idge connector)
STB
Bur
ner ther
mostat
Inter
nal three-w
a
y
re
v
ersing v
alv
e
for mains w
ater
(A
C oper
ation)
Digital Room
Controller
I/O
comm
unication por
t
T
u
rn-on v
oltage f
o
r
e
xter
nal, customer-supplied
three-w
a
y
re
v
ersing v
alv
e
(A
C oper
ation)
Br
idge is conductiv
e
(remo
v
e
when connecting)
Loop is non-conducting
(remo
v
e
when connecting)
UBA connection b
loc
k
Bur
ner-control unit (UBA)
Fuse 1.25 slo
w b
lo
w
2
1
2
1
1
2
1
2
e
xter
nal
230V controls
V
olt free e
xter
nal
control de
vice
*) remo
v
e
wirebr
idge
when used
V
olt free room
ther
mostat
when used with
230V timer *)
IMP
O
RTANT
Th
e wi
res in
this ma
in
s
le
ad
a
re co
lo
ure
d
in
acco
rd
an
ce
wi
th
the
fo
llo
win
g co
de
:
GRE
E
N
A
ND YE
LLOW - E
ARTH ; BLU
E
- NE
UTRA
L
;
B
R
OWN - LIVE
As t
he
col
ou
rs
of
the
w
ire
s i
n t
he
ma
in
s l
ead
of o
f t
he
app
liance
m
ay n
ot
cor
re
spo
nd
w
ith
the
col
ou
red
ma
rk
in
gs
id
en
tifyi
ng
the
te
rm
ina
ls in yo
ur
p
lu
g p
rocee
d
as fo
llo
w
s:
The
w
ire
col
ou
red
gr
ee
n a
nd
yel
lo
w
m
ust be
co
nne
cte
d to
th
e t
er
m
in
al
o
n th
e p
lug
m
ar
ked
w
ith
th
e
le
tte
r
E o
r b
y th
e e
ar
th
sym
bo
l
o
r
col
ou
re
d
gr
ee
n o
r
gr
ee
n-
an
d-
yel
lo
w
. Th
e w
ire co
lo
ur
ed
b
row
n m
ust be
co
nne
cte
d to
th
e t
er
m
in
al
m
ar
ked
w
ith
the
let
ter
L
or
co
lo
ur
ed
r
ed
. The
wire
colo
ur
ed
blu
e m
ust
be
con
ne
cted
to
the
te
rm
ina
l m
ar
ked
with t
he
lette
r N or
co
lo
ur
ed
bla
ck.
W
ARNING
THIS
AP
PLIANC
E MUS
T
BE
EAR
T
HED
E
ns
ure
th
at
y
our
a
pp
lia
nc
e is
c
on
ne
ct
ed
c
or
rec
tly
- if
y
ou ar
e in
an
y do
ub
t c
on
sult
a q
ua
lif
ie
d e
le
ctr
ic
ia
n.
WARNING!
Do not connect 230V to the connection block on the UBA.